Baking with multiple Maps Question
This time I'm adding screenshots :)

Once you have your model assigned the 3 materials

1: Select the Head material. 

2: In the UV/Image editor, create a new image for the head to bake to.

3: In the Node editor add a New Image node and select the Head image as reference.



Repeat for the other 2 materials.

Note: It is very important that you leave the Image node selected (highlighted) for each material. If an Image node is not selected then that material will not be baked !

4: Select all of the mesh.

5: When you have your baking options setup hit the Bake button. All 3 materials will be baked, each to its own image.

When the baking is finished only one of the three will be visible in the UV/image editor. 

 

6: Go to the UV/Image editor and one by one select each of the three images and save them some where for later use.